Attention recently has been directed to implementing voice telephone service over the worldwide network now commonly known as the Internet. The Internet had its genesis in U.S. Government (called ARPA) funded research which made possible national internetworked communication systems. This work resulted in the development of network standards as well as a set of conventions for interconnecting networks and routing information. These protocols are commonly referred to as TCP/IP. The protocols generally referred to as TCP/IP were originally developed for use only through Arpanet and have subsequently become widely used in the industry. TCP/IP is flexible and robust, in effect, TCP takes care of the integrity and IP moves the data. Internet provides two broad types of services: connectionless packet delivery service and reliable stream transport service. The Internet basically comprises several large computer networks joined together over high-speed data links ranging from ISDN to T1, T3, FDDI, SONET, SMDS, OT1, etc. The most prominent of these national nets are MILNET (Military Network), NSFNET (National Science Foundation NETwork), and CREN (Corporation for Research and Educational Networking). In 1995, the Government Accounting Office (GAO) reported that the Internet linked 59,000 networks, 2.2 million computers and 15 million users in 92 countries.
Referring to FIG. 11 there is shown a simplified diagram of the Internet. Generally speaking the Internet consists of Autonomous Systems (AS) which may be owned and operated by Internet Service Providers (ISPs) such as PSI, UUNET, MCI, SPRINT, etc. Three such AS/ISPs are shown in FIG. 11 at 410, 412 and 414. The Autonomous Systems (ASs) are linked by Inter-AS Connections 411, 413 and 415. Information Providers (IPs) 416 and 418, such as America Online (AOL) and Compuserve, are connected to the Internet via high speed lines 420 and 422, such as T1/T3 and the like. Information Providers generally do not have their own Internet based Autonomous Systems but have or use Dial-Up Networks such as SprintNet (X.25), DATAPAC and TYMNET.
By way of current illustration MCI is both an ISP and an IP, Sprint is an ISP, and MicroSoft (MSN) is an IP using UUNET as an ISP. Other information providers, such as universities, are indicated in exemplary fashion at 424 and are connected to the AS/ISPs via the same type connections here illustrated as T1 lines 426. Corporate Local Area Networks (LANs), such as those illustrated in 428 and 430, are connected through routers 432 and 434 and links shown as T1 lines 436 and 438. Laptop computers 440 and 442 are representative of computers connected to the Internet via the public switched telephone network (PSTN) are shown connected to the AS/ISPs via dial up links 444 and 446.
The Information Providers (IPs) constitute the end systems which collect and market the information through their own servers. Access providers are companies such as UUNET, PSI, MCI and SPRINT which transport the information. Such companies market the usage of their networks.
In simplified fashion the Internet may be viewed as a series of routers connected together with computers connected to the routers. In the addressing scheme of the Internet an address comprises four numbers separated by dots. An example would be 164.109.211.237. Each machine on the Internet has a unique number which constitutes one of these four numbers. In the address the leftmost number is the highest number. By analogy this would correspond to the ZIP code in a mailing address. At times the first two numbers constitute this portion of the address indicating a network or a locale. That network is connected to the last router in the transport path. In differentiating between two computers in the same destination network only the last number field changes. In such an example the next number field 211 identifies the destination router. When the packet bearing the destination address leaves the source router it examines the first two numbers in a matrix table to determine how many hops are the minimum to get to the destination. It then sends the packet to the next router as determined from that table and the procedure is repeated. Each router has a database table that finds the information automatically. This continues until the packet arrives at the destination computer. The separate packets that constitute a message may not travel the same path depending on traffic load. However they all reach the same destination and are assembled in their original order in a connectionless fashion. This is in contrast to connection oriented modes such as frame relay and ATM or voice.
One or more companies have recently developed software for use on personal computers to permit two-way transfer of real-time voice information via an Internet data link between two personal computers. In one of the directions, the sending computer converts voice signals from analog to digital format. The software facilitates data compression down to a rate compatible with modem communication via a POTS telephone line. The software also facilitates encapsulation of the digitized and compressed voice data into the TCP/IP protocol, with appropriate addressing to permit communication via the Internet. At the receiving end, the computer and software reverse the process to recover the analog voice information for presentation to the other party. Such programs permit telephone-like communication between Internet users registered with Internet Phone Servers.
The book "Mastering the Internet", Glee Cady and Pat McGregor, SYBEX Inc., Alameda, Calif., 1994, ISBN 94-69309, very briefly describes three proprietary programs said to provide real-time video and voice communications via the Internet.
U.S. Pat. No. 4,872,197, issued Apr. 21, 1987, to Dorsey et al., titled Verbal Computer Terminal System, describes a system for providing voice telephone access to computers. The system is one wherein remote computers of a conventional type may be addressed or accessed by multiple DTMF telephones and respond or provide output to such telephones in the form of speech derived from the data bases of the respective computers. The system includes means between the standard computer and the DTMF input and analog audio output for emulating computer terminals acceptable to the host computer, for example for converting text data from the computers into speech signals transmissible over telephone line to a caller.
Several providers of Internet telephony software now offer along with the software the use of Internet Phone Servers. These servers, usually in distant cities, are available for users of the software to choose in order to connect to connect to the Internet Phone Network of the particular software provider. In a sense, the servers fulfill the function of a phone directory to access other Internet Phone users. When users of the software connect to the Internet Phone server they are provided with a list of other connected users. From this list a choice may be made and the user can make calls to the other connected parties. In addition to this telephone directory type listing the connected users are also listed under sublists of topics of conversation. Thus the service is similar to the so called "chat rooms" that are available from ISPs for keyboard to keyboard communication. The obvious shortcoming of the service from a telephony standpoint is an inability to make a call to a telephone subscriber who may or may not own a computer or who may not be on line at the time that the calling party desires to establish a contact.
Palmer et al. U.S. Pat. No. 5,375,068, issued Dec. 20, 1994 for Video Teleconferencing for Networked Workstations discloses a video teleconferencing system for networked workstations. A master process executing on a local processor formats and transmits digital packetized voice and video data, over a digital network using TCP/IP protocol, to remote terminals.
Lewen et al. U.S. Pat. No. 5,341,374, issued Aug. 23, 1994 for Communication Network Integrating Voice Data and Video with Distributed Call Processing, discloses a local area network with distributed call processing for voice, data and video. Real-time voice packets are transmitted over the network, for example to and from a PBX or central office.
Hemmady et al. U.S. Pat. No. 4,958,341, issued Sep. 18, 1990 for Integrated Packetized Voice and Data Switching System, discloses an integrated packetized voice and data switching system for a metropolitan area network (MAN). Voice signals are converted into packets and transmitted on the network. Tung et al. U.S. Pat. Nos. 5,434,913, issued Jul. 18, 1995, and 5,490,247, issued Feb. 6, 1996, for Video Subsystem for Computer Based Conferencing System, disclose an audio subsystem for computer-based conferencing. The system involves local audio compression and transmission of information over an ISDN network.
Hemmady et al. U.S. Pat. No. 4,872,160, issued Oct. 3, 1989, for Integrated Packetized Voice and Data Switching System, discloses an integrated packetized voice and data switching system for metropolitan area networks.
Sampat et al. U.S. Pat. No. 5,493,568, issued Feb. 20, 1996, for Media Dependent Module Interface for Computer Based Conferencing System, discloses a media dependent module interface for computer based conferencing system. An interface connects the upper-level data link manager with the communications driver.
Koltzbach et al. U.S. Pat. No. 5,410,754, issued Apr. 25, 1995, for Bi-Directional Wire Line to Local Area Network Interface and Method, discloses a bi-directional wire-line to local area network interface. The system incorporates means for packet switching and for using the internet protocol (IP).
As the use of the Internet for a multitude of business and consumer purposes has grown traffic problems and bottlenecks have appeared and increased in seriousness. As the success of commercial Internet Service Providers (ISPs) has expanded their network traffic has grown to the extent that service is slow and detrimental to efficient usage as well as to continued expansion. At the same time that overload has been experienced on the Internetwork side it is now clear that isolated but growing overloading is beginning to occur in the telephone network connection to the ISPs and to routers of the telephone companies providing Internet access. This presents a serious problem to the ability of the consumer to avail themselves of the efficient and economical advantages that the Internet is capable of providing.